To observe or not to observe 9/11?

It’s an observance I’ve taken for granted these past 9 years. On this 10th anniversary, we do it again to honor and remember both the living and dead heroes of 9/11…and their families. Earlier this week, a friend told me that she believes that the terrorists love the observances. She said it allows them to relive again what they consider to be their triumphs of that day in 2001. Do you think her point of view has any merit?